Sometimes when I run a terminal command that updates or installs software, the transaction displays a curl error in red but still finishes successfully. It does not happen every time, and I have heard that the package manager may simply retry or use another download mirror. I'm new to Linux, so I'm unsure whether this is normal terminal noise or a sign of a security problem, a broken installation, or a compromised system. How should I interpret these errors, and when should I take action?
2 Answers
For installing software, it is generally safest to use your distribution’s official repositories and package manager. Many systems also provide a graphical software center, and Flatpak applications can be installed through trusted sources such as Flathub. Avoid downloading random installers or mixing packages from unrelated distributions and releases, since that can create dependency and maintenance problems.
It depends on the specific curl error, but a common cause is a package mirror being temporarily unavailable, timing out, or refusing a connection. Package managers often try another mirror, so the overall transaction can still complete successfully. If the update finishes and all packages are installed correctly, it usually is not a security warning. If it happens repeatedly, several mirrors fail, or the package manager reports that packages could not be downloaded or configured, refresh or review your mirror list and investigate the exact message.
Having a lot of software installed by itself does not create a broken mixed system. The bigger risk is combining packages from different distributions, releases, or third-party repositories that replace core system components.